Edge shearing device for sewing machines



Nov. 19, 1935.

B. PUGACH EDGE SHEARING DEVICE FOR SEWING MACHINES Filed June 22, 19:55

Patented Nov. 19, 1935 UNITED STATES PATENT OFFICE EDGE SHEARING DEVICE FOR SEWING MACHINES 3 Claims.

This invention relates to mechanism for shearing the edges of cloths as they are being stitched to each other in the sewing machine, and its principal object is to provide a simplified, conveniently and economically manufacturable and salable, efficiently utilizable and operable, reliable, strong, durable, and improved device for this purpose.

Another object is to provide a device for this purpose which is attachable to and detachable and completely removable from the sewing machine, whereby the latter may be operated either with or entirely without the presence of such mechanism.

Other objects and advantages will hereinafter appear.

In the accompanying drawing,-

Fig. 1 is an elevation of the device constituting the invention.

Fig. 2 is a plan view of the device and mechanism shown in Fig. 1.

Fig. 3 shows a transverse-sectional end elevation of the device shown in Fig. 1.

To the needle plate I seated upon the table 2 of the sewing machine is secured, by means of screws 3, a. framing 4 in which is wedged a plate 5 having a shearing edge 6 adjacent to the usual needle I projecting from the needle bar 8 operating reciprocatingly from the head 9 of the machine. The shearing plate 5 is firmly maintained in adjusted operative position, by means of a setscrew l threading through a lug ll of framing 4 and pressing it against ledges l2 of said framing and the surface of the usual needle plate I. In a bearing l3 of framing 4 is journaled a rockable rod 14 having a head l to which is secured a cooperating shearing arm I6. At the opposite end of the framing 4 is journaled a rock-shaft I! in a pair of lugs l8 forming part of the framing, and to the extremity of said shaft is secured by a set screw IS a fitting 20 in which is longitudinally slidable a connecting rod 2| pivotally joined at its terminal 22 to the needle bar 8 as shown. The other end of shaft I! carries an arm 23 to which is pivoted a link 24, which is in turn pivoted to an arm 25 carried by the bar [4. The regular vertical reciprocating movement of the needle bar 8 is thus transmitted by the connecting rod 2| into a reduced oscillating motion of the fitting 20, which accordingly rocks the shaft l1 and transmits through link 24 and arms 23, 25 a corresponding rocking action to the bar 14, whereby the shearing arm I6 is properly oscillated to coact with the shearing plate 5 to cut the edgings of the cloths as required simultaneously withthe stitching work while the sewing proceeds. A spring 26 curled around the bar 14 and located between bearing l3 and the arm 25 presses against the latter to normally draw the shearing arm l6 toward the shearing plate 5. A thumb-screw 21 threading through a lug 28 of the framing 4 may be pressed against the terminal of the bar l4, as shown in Fig. 3, to thereby adjust the position of the shearing arm l6 relatively to th shearing plate 5, as may be required by the various thicknesses or other conditions of the cloth materials to be worked upon.

When it is desired to use the sewing machine without any shearing function, this device and mechanism may be very conveniently and completely removed entirely from the machine by merely unthreading the screws 3 and the screw 29 of pivot 22, and the device may be as readily restored into operative coaction with the sewing machine.

Variations may be resorted to within the scope of the invention, and portions of the improvements may be used without others.

Having thus described my invention, I claim:-

1. In a sewing machine having a needle and a needle bar therefor, a shearing device for cloth edges having the combination of a pair of shear ing elements, an axle carrying one of said elements, a rock shaft, guiding means carried by said shaft, a connecting rod pivoted to said needle bar being slidable in said'means, linkage joining said shaft and axle, and the motion of said needle bar rocking said shaft through said connecting rod to transmit rocking action to said axle through said linkage to actuate said element.

2. In a sewing machine having a needle and a needle bar therefor, a shearing device for cloth edges having the combination of a pair of shearing elements, an axle carrying one of said elements, a framing attachable to and detachable from the sewing machine, the other of said elements carried by said framing, said axle pivoted in said framing, a shaft mounted to rock in said framing, guiding means carried by said shaft, a connecting rod pivoted to said needle bar being slidable in said means, linkage joining said shaft and axle, and the motion of said needle bar rocking said shaft through said connecting rod to transmit rocking action to said axle through said linkage to actuate said element carried thereby.

3. In a sewing machine having a needle, a needle bar therefor, and a needle plate, a shearing device for cloth edges having the combination of a framing attachable to and detachable from said 2- I I I 2,021,700

needle plate, a pair of shearing elements, one of said elements being held by said framing, an axle pivoted in said framing carrying the other element, a shaft mounted to rock in said framing, guiding means carried by said shaft, a, connecting rod pivoted to said needle bar being slidable in said means, linkage joining said shaft and axle, and the motion of said needle bar rocking said shaft through said connecting rod to transmit rocking action to said axle through said linkage to actuate the element carried thereby.

BARNET PUGACH. 

